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So, our company uses Google Apps for it's email hosting (aming other things), however something very strange occurs pretty regularly- email messages sent from external MTAs (i.e., T-Mobile's Blackberry e-mail service, a notification service sent by an external company that a company we have a contract with, etc.) sometimes take several hours to deliver into some of our mailboxes.

Is there any reason this happens regularly? I have verified myself that our MX records match what Google says they should be. Is there anything that I'm missing, perhaps?

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No, you're not missing anything.

You may find that Google is doing greylisting behind the scenes. I know from personal experience that Road Runner ( is notorious for allowing spammers on their network. So Google may be forcing the MTAs to resend the messages with a specific timeout.

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If the "external" mail servers are always the same, adding them in an SPF record about your domain. – adamo Nov 6 '10 at 19:30
But it's not just, and isn't all the time. We receive automated email from a company called Laker Software, and they have email notifications whenever we submit .csv files to them and they get processed Those queue up for sometimes half a day, and then I'll sometimes get a batch of 60 emails for that exact duration. – Robert Butler Nov 6 '10 at 19:31
@adamo Eh? Say what now? – Robert Butler Nov 6 '10 at 19:33
I was using as an example, but check with Laker Software that there isn't an SPF issue with your domain. You may be greylisted yourself in some RBL. – user3914 Nov 6 '10 at 19:35
@Randolph Thanks. How would I find out if we've been greylisted? And more importantly, how would we become un-greylisted? (if indeed that is the case) – Robert Butler Nov 6 '10 at 19:39

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